Not Sure I Like the Soiree Design

The Soire design requires you to us to a plastic Unift adapter, so the flush is not straight down. The Unift adapter, with its curved shape, would seem to be a cause for potenial clogs over the long term. Plus, you need to put 2 extra screw holes in the back of your floor to hold down the adapter....versus using only 2 bolts to connect the toilet to the drain flange. Plus, the weight of the toilet on the seal is not straight down either. It seems to me a straight down seal with the bowl weight on top of it is much less likely to leak over time, versus the Soiree design with a back seal that is cantilevered to the main drain flange seal.

Seems like I would be better off with a more standard design to replace my 39 yaer old 4/5 gallon Kohler Wellington. My Kohler has the bolts to the drain flange at about 13 inches from the back wall, so there is plenty of room.

If you don't like the Soiree, then there is no need to buy it. It's a free market. As a practical matter, you pick the Toto that looks nicest to you, in the right price range for you, and it will work fine. Don't worry about the engineering.

I can see why you think what you think, but I think the only point that's sort of valid from an engineering perspective is that you have to spend an extra 10 minutes to install two extra screws.

I'll give you just an outline of my thoughts; I am sure others will fill in in more detail:

(1) No flush goes "straight down". All toilets have a trapway, because there's no trap in the waste pipe.

(2) Modern trapways for Toto low-flow toilets are designed with curves specifically to prevent clogs.

(3) The Unifit simply replaces a portion of the china trapway in the toilet with a floor-mounted portion that can come in three lengths.

(4) Far from being prone to "potential clogs" in comparison to something that goes "straight down", Toto's trapway design is considered the best in the business and they certainly put more resources into trapway design and redesign than anyone else. It's the design of the siphon and trapway that enables them to to do a 1.0gpf toilet coming on the market soon.

(5) The weight of the toilet is indeed straight down. Nothing is cantilevered. I think I see what you're trying to say, but I don't think the engineering works the way you are thinking it does. The floor bears the weight of the toilet evenly along its entire length; the weight is not concentrated on one point.

(6) You seal up the connection to the waste pipe nice and tight, so no leaks will happen there, and the male-female connection in the rear is nice and tight as well. I have no concerns about my Carlyle II leaking. None.

If you want the Soiree but are concerned about the engineering of the trapway, don't be. If you don't much like the Soiree, pick another Toto. In either event, enjoy the flush!

I'm a do-it-yourself homeowner and I installed a Soiree in my downstairs bathroom a few years ago. Yes, you have to drill those 2 holes and in my case through ceramic tile, but with the right bit it was easy.

I know the plastic UniFit adapter looks like it wouldn't work -- but guess what -- the great engineers at Toto actually tested it! I have never had a clog in that toilet in the 5 years it's been installed, and I can assure you it's had a good workout.

One advantage of the UniFit system is that if and when you want to pull the toilet up (say, to paint or wallpaper behind it), it is EXTREMELY easy -- you just unbolt the toilet, and lift up. To replace it, you set it on the UniFit and bolt it down. No messy wax rings to deal with!

FWIW, in most places, it is code to seal the base of the toilet (at least the front 3/4 or so) with caulk to prevent drips, misses, dirty mop water, etc., from getting underneath the edge and then festering. Done properly, this will anchor any toilet to the floor quite well, bolts almost optional. I've got a couple of Totos that use the Unifit, and in nearly 10-years have never had a clog. The old ones I took out needed a plunger, and used over twice as much water to flush. The nice smooth curves possible with the adapter make it really tough to clog. A fully porcelain trapway can sag a little after coming out of the mold, and there's no guarantee it is as consistent. Plus, if you look at some toilets, you'll notice that the waste needs to make nearly a short 90-degree turn to get to the drain. Routing that in nice smooth curves is MUCH more reliable and harder to clog.

Thanks for all the comments. Just a note for clarification on the below comment from wjcandee:

"(6) You seal up the connection to the waste pipe nice and tight, so no leaks will happen there, and the male-female connection in the rear is nice and tight as well. I have no concerns about my Carlyle II leaking. None"

Does this mean there no wax rings used on either end of the UniFit adapter? If yes, how does it seal at each end?